<template>
  <el-breadcrumb class="app-breadcrumb ml-4" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span v-if="(item.redirect === 'noRedirect') || (index === levelList.length - 1)" class="no-redirect">{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script>
import pathToRegexp from 'path-to-regexp'

export default {
  data () {
    return {
      levelList: null
    }
  },
  watch: {
    $route () {
      this.getBreadcrumb()
    }
  },
  created () {
    this.getBreadcrumb()
  },
  methods: {
    getBreadcrumb () {
      // only show routes with meta.title
      const matched = this.$route.matched.filter(item => item.meta && item.meta.title)

      this.levelList = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
    },

    pathCompile (path) {
      const { params } = this.$route
      const toPath = pathToRegexp.compile(path)
      return toPath(params)
    },

    handleLink (item) {
      const { redirect, path } = item
      if (redirect) {
        if (this.$route.fullPath === redirect) {
          return
        }

        this.$router.push(redirect)
        return
      }
      this.$router.push(this.pathCompile(path))
    }
  }
}
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  height: 30px;
  line-height: 30px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
